The present invention relates to a metallic golf club head having a hollow space therein.
Recently, golf club heads that are larger than conventional ones and have a flatter shape to yield a high moment of inertia have become commercially available. Although the club heads of this type have an advantage in being able to yield a high moment of inertia, they have a problem in that the natural frequency of the head is low, and therefore a low and muffled hitting sound, which is generally displeasing, is produced. If the head volume is increased to its limits within the range of specified weight, the wall thickness of head decreases, and also the head has a flatter shape, so that the areas of the sole and the crown increase. As a result, the natural frequencies of the sole and the crown decrease, which may adversely affect the hitting sound.
Japanese Unexamined Patent Application Publication No. 10-24128 describes a technique in which, in the hollow space of the golf club head, a plate-shaped rib for adjusting the hitting sound is provided on the inner surface of the sole only. Also, Japanese Unexamined Patent Application Publication No. 2002-186691 describes a technique in which, in the hollow space of the golf club head, plate-shaped ribs for adjusting the hitting sound are provided from the inner surface of the sole to the inner surface of a side.